Some people disable the Speedtouch's firewall just to enable the icmp-echoreply, which is not correct, here is how to enable the icmp-echoreply on Speedtouch.

First login to the Speedtouch's CLI using telnet, the default ip of the speedtouch is 10.0.0.138.

By default the speedtouch comes without username and password, just press Enter on the username prompt, or type your username and password.

On the speedtouch command prompt, copy and past the following:

:firewall chain create chain=input
:firewall chain create chain=sink
:firewall chain create chain=source
:firewall chain create chain=output

Then... the following:

:firewall assign hook=input chain=input
:firewall assign hook=sink chain=sink
:firewall assign hook=source chain=source
:firewall assign hook=output chain=output

Then... the following:

:firewall rule create chain=input index=0 dstintfgrp=wan prot=icmp icmptype=echo-request action=accept
:firewall rule create chain=sink index=0 dstintfgrp=wan prot=icmp icmptype=echo-request action=accept
:firewall rule create chain=source index=0 dstintfgrp=wan prot=icmp icmptype=echo-reply action=accept
:firewall rule create chain=output index=0 dstintfgrp=wan prot=icmp icmptype=echo-reply action=accept

Finally:

Saveall

Now ping your wan ip from http://network-tools.com/

If you want to know more about speedtouch firewall, check these sites:

http://www.speedtouch.nl/docs/AppNotes/AppNote_Firewalling.pdf

http://www.fredshack.com/docs/alcatel.html